Charge pump operation in a non-volatile memory device

Abstract

A charge pump in a memory device is activated to produce a programming voltage prior to data loading during a programming operation. During an initial programming cycle, first and second load voltages are charged from the charge pump. The first load is removed from the charge pump during a verify operation. The first load voltage is subsequently recharged by charge sharing from the second load voltage so that the charge pump is not initially necessary for recharging the first load voltage.

1. A method for operating a memory device comprising a charge pump circuit having a charge pump, a first load coupled to the charge pump through a first switch, a second load coupled to the charge pump through a second switch and a third switch coupling the first load to the second load, the method comprising:
 receiving an address load command; 
 generating a program enable signal in response to the address load command; and 
 turning on the charge pump in response to the program enable signal and prior to a data loading operation. 
 
     
     
       2. The method of  claim 1  and further including:
 increasing, during a first cycle, a second load voltage on the second load; and 
 increasing, during a second cycle, a first load voltage on the first load, in response to activating the third switch. 
 
     
     
       3. The method of  claim 2  and further including activating the first switch after the first load voltage reaches a predetermined level. 
     
     
       4. The method of  claim 1  and further including charge sharing from the second load to the first load through the third switch during a second cycle.